Rustless pipe for war and peace

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URBANA

'f-LlffOIS STATE GEOLOGICAL SURVEY

3 3051 00003 5240

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in 2012 with funding from

University of Illinois Urbana-Champaign

http://archive.org/details/rustlesspipeforw120squi

STATE OF ILLINOIS

DWIGHT H. GREEN, Governor

DEPARTMENT OF REGISTRATION AND EDUCATION

FRANK G. THOMPSON, Director

DIVISION OF THE

STATE GEOLOGICAL SURVEY

M. M. LEIGHTON, Chief
URBANA

CIRCULAR—NO. 120

RUSTLESS PIPE FOR WAR AND PEACE

BY

FREDERICK SQUIRES

REPRINTED FROM THE OIL. AND GAS JOURNAL
VOL. 44, NO. 13, AUGUST 4, 1945

PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS

J SL

RBANA, ILLINOIS
1945

RUSTLESS PIPE FOR WAR AND PEACE

By FREDERICK SQUIRES

Introduction

fML, gas, soil, air, and salt water
^ attack and shorten the life of
oil-field steel. Of these enemies, salt
water is the most destructive. The
use of nonmetallic pipe helps to
answer the wartime demand for
"more oil with less steel," and since
there is no V-Day in the endless
fight of rust against steel, whatever
helps in war will be helpful when
war is over. With this in mind, the
Illinois State Geological Survey set
up the project of investigating cor-
rosion-proof pipe and couplings, the
results of which are described here.
An earlier project, along related

lines, resulted in the successful run-
ning and cementing of fiber-pipe
casing in a 500-ft. well, an opera-
tion described in The Oil and Gas
Journal for May 28, 1942.

Scope of the Investigation

The most satisfactory corrosion-
proof pipe-forming materials were
found to be of the following com-
positions: (1) coal-tar pitch with a
binder of macerated paper and wood
fiber; (2) cement with a binder of
asbestos fiber, and (3) both plain
and reinforced plastics.

We made pipe which we called
"Glascrete," consisting of highly

failed at le.ooo

LB. COMPRESSION

NO. 4.5.6.17 SHOWED NO LEAKS
UNDER 200 P S I AIR PRESSURE

CROSS SECTION
OF PIPE EQUALS
SECTION OF
COUPLING

FAILEO AT 29.200
L& TENSION

WITHSTOOD 28.700
LB. TENSION

Fig. 1 — Seven methods of coupling asbestos cement pipe

Fig. 2 — (Left) A section of asbestos cement pipe at 1,
joint 4 at 2. joint 6 at 3, joint 3 at 4, and joint 5 at 5

Fig. 3 — (Right) The joints after being tested to lailu
Points of failure are indicated for each joint in Fig.

compressed cement with glass-fiber
reinforcement which we tested and
found incapable of withstanding
shock and suddenly applied loads.
However this experiment suggested
the substitution of plastics, rein-
forced with glass, for cement. We
found that threaded couplings made
of cast iron, steel, stainless steel and
plastic, either plain or reinforced
with glass fiber or metal, could be
used on threaded asbestos-cement
pipe. This pipe seemed to require
couplings of a material more elas-
tic than the pipe itself. Stainless
steel and plastic pipe were found to
be too expensive for a complete as-
sembly, but couplings of these ma-
terials, used to join lengths of fiber
or asbestos-cement pipe, were suf-
ficiently economical in view of the
small fraction of the entire pipe line
occupied by the couplings.

Sections of fiber, asbestos-cement,
and plastic pipe were tested for
ability to resist bursting and col-
lapse. Pipe and coupling assemblies
were tested for strength to resist
parting both in the pipe and at the
joint, and leakage at the joint. Non-
metallic pipe lines have heretofore
been connected by means of a va-
riety of shoved joints, made tight
either by friction holds or rubber
gaskets. The couplings which, be-
cause of the greater strains on them,

should be the stronger part of non-
metallic pipe lines, have always
been the weaker, because advan-
tage has never been taken of the
great inherent strength of a threaded
connection. A good deal of time was
devoted to the problem of thread
ing pipe and couplings with results
which seemed to be promising. It
was found that threading by grind-
ing with high-speed abrasive wheels
overcame many of the difficulties
previously thought to be insur-
mountable. Couplings were made of
asbestos cement, cast iron, steel,
stainless steel, plain plastic, and
glass-fiber and metal - reinforced
plastic. Tests were made on the pipe
alone and on the pipe and coupling
assembled.

Fiber Pipe Tests

The composition of fiber pipe is
75 per cent coal-tar pitch and 25
per cent macerated paper and wood
fiber. It is made on mandrels in 5
and 8 ft. lengths. Designed origi-
nally for use as electric conduit, it
has been successful for this purpose
under a wide variety of conditions
for many years. The weight of fiber
pipe is only 16 per cent of the weight
of steel pipe of equal cross-section.

Fiber conduit is made to meet
three classifications. The second of
these three commercial grades was

tested for strength at Halliburton
Oil Well Cementing Co.'s Flora
plant. The pipe was destroyed by
bursting at an average pressure of
220 psi. Collapse occurred at 420
psi. Ultimate tensile strength was
2,500 psi., and ultimate compressive
strength 5,000 psi. These degrees of
strength prove it is usable for grav-
ity lines and for cemented-in cas-
ing for shallow wells.

No leakage tests were made be-
cause of the nature of the joint.
Pipe supplied us was not threaded
but the joint was made by tapering
the end of the pipe and driving it
into an oppositely tapered coupling.
The elasticity of the coupling binds
the pipe and provides a friction
grip. The ability of such a joint to
resist separation varies over a con-
siderable range and is therefore not
reliable except for surface gravity

lines. Threaded fiber-pipe joints
connected by threaded stainless steel
or plastic couplings provide a prac-
tical corrosionproof string for sur-
face lines and for cemented-in cas-
ing for shallow wells. The plastic
couplings are stronger than the pipe,
and the joint is leakproof.

Tests with dilute acids and alka-
lis did not affect the fiber pipe, and
immersion in crude oil for 8 months
produced only a slight tackiness of
the exposed surfaces. These corro-
sion-resisting qualities make it es-
pecially useful for salt-water dis-
posal, both for surface lines and for
short strings of subsurface casing.

The main difficulty with the pipe
of this composition is that severe
shocks such as are often experienced
in shipment and other handling may
produce crazing, which is difficult
to detect but which weakens the

4 — Joints 1 and 2 (shown also in scale sections on Fig.
J and a section of similar asbestos cement pipe for com-
■iscn. JVc tension test was made, but compression tests
t-.troyed joint 1 (center) at 21.000 lb. and joint 2 (right)
c 18.000 lb. The pipe (leit) tailed in compression at
2200 lb., shewing that the joints weakened the pipe
I. 5 — (Right) Testing machine in the Talbot laboratory on
tich all the tests were made. The joint being tested is

shewn in Fig. 1 as No. 5. the 6-in. pipe coupling

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pipe. It is also subject to the defect
of cold bending under its own
weight. To correct both these im-
perfections as well as to increase its
strength for every kind of load, the
pipe may be cement lined by the
same process that is used to protect
metal pipe against corrosion. Ce-
ment-lined fiber pipe may be fur-
ther strengthened by first incorpo-
rating coiled - wire reinforcement
sprung against the inside of the pipe
and then cementing it in, the re-
sulting reinforced cement inner
sheath providing a great increase in
the pipe's resistance to bursting.
This makes the pipe suitable for
pressure lines on the surface and
cemented-in casing for deeper wells.

Asbestos-Cement Pipe

Asbestos-cement pipe is made on
mandrels which pick up a coating of
cement, water, and asbestos fiber. A
roller above the mandrel subjects
the coating to high pressure while
it is being built up. It is made in
several grades, from flue pipe at the
bottom of the scale up to pipe that
stands 200-lb. pressure.

Commercial lengths are 13 ft.
Couplings are made in a variety of
ways but none are threaded so that
when used in any but a horizontal
position the line must be supported
to keep it from pulling apart. The
usual uses are for electric conduits,
vent pipes, and water mains. It has
been used as a well casing with
screwed joints in only one installa-

tion. Brundred Oil Co. has used this
pipe with perforated beveled tele-
scoping joints for liners for the bot-
tom hundred feet of oil wells in
Pennsylvania.

Tests of Joints for Asbestos-
Cement Pipe

Seven kinds of experimental
joints for asbestos-cement pipe were
devised and tested and are illus-
trated by scale drawings in Fig. 1
and by photographs in Figs. 2, 3,
and 4.

Joint No. 1 was made by beveling
two pieces of low-strength 3-in. i.d.
flue pipe and joining them by a
coupling consisting of two eccentric
metal cylinders held together at the
center by a metal ring. The inner
metal cylinder was cast iron and
the outer was light-weight spiral
pipe. The inner metal ring and
the pipe were grooved for a me-
canical bond that would be formed
when the space between the inner
metal ring and the pipe is filled
with any setting material poured in
and allowed to harden. The bond in
this case was made with sulfur.

The joint was tested to failure by
compression at 21,600 lb. It was not
tried in tension.

Joint No. 2 consisted of male and
female tapered 3-in.-i.d. asbestos ce-
ment-flue pipe and a single outside
cylinder of light-weight steel spiral
pipe, all bonded with sulfur poured
into the space between the ring and
the inner pipe section, after which

Fig. 6 — Equipment ior leak lest, showing joinf 6 (Fig. 1) being tested
with air at 200 psi. Joint 4 is in background ready to be tested

Fig. 7 — The press and dies used in making and the hydraulic pump used in testing glass-
iiber-reiniorced cement pipe, and plain and reinforced plastic couplings. The test pieces
of glasscrete (glass-fiber-reiniorced cement) pipe and plastic couplings are made under
high pressure in the press and are tested with the hydraulic pump lor strength to

resist bursting

the outer section was run into place.
This joint was destroyed in compres-
sion at 18,000 lb. Joints 1 and 2 are
shown in Fig. 4.

A section of 3-in. i.d. asbestos-ce-
ment flue pipe (also shown in Fig. 4)
was destroyed in compression in or-
der to compare its behavior with
that of the jointed pipe. It failed at
25,200 lb. showing that the joint was
weaker than the pipe.

Joint No. 3 was made to provide
a joint with a positive mechanical
bond between the two pieces of ta-
pered male and female 3-in. -i.d. as-
bestos-cement flue pipe and a cast-
iron outer cylinder. Grooves were
cut to register in both pipe and cou-
pling and the hollow ring so formed
was poured full of type metal. The
joint proved stronger than the pipe.
(Joints 1, 2 and 3 were made with
low-strength pipe and are not com-
parable with the following tests
made on 200-lb. pipe. They would
be too weak and too slow in assem-
bly to be practical in the oil field)

Joint No. 4 consisted of a cast-iron
screwed coupling connecting two
sections of 5-in.-i.d. 200-lb. threaded
asbestos-cement pipe. The threads
are one to the inch, the cross-section
of the metal thread being one-fourth
of the cross-section of the asbestos-

cement thread. (Fig. 10). The threads
were made by grinding (Fig. 11). The
smaller section of the metal presents
greater strength to resist stripping
than the greater section of pipe, as
was shown in the test wherein the
joint failed in the pipe thread. This
idea should be incorporated in the
design of any metal coupling for
nonmetallic joints of pipe.

Joint No. 5 is a standard steel 6-in.
i.d. line collar, eight threads to the
inch, connecting two sections of
5-in.-i.d. 200-lb. asbestos - cement
pipe threaded on a standard pipe-
threading machine. It is the simplest
joint to make because all the work
is standard steel pipe practice. (The
thread on the pipe should be ground
with an abrasive wheel, not cut on
a pipe machine.) The test of this
pipe compared with the coarser,
deeper-cut threads on joint No. 4
just described and joints Nos. 6 and
7 give evidence that the best num-
ber of threads per inch for asbestos-
cement joints should be somewhere
between eight and one thread per
inch. Four is suggested. A stain-
less-steel coupling should replace
the ordinary steel. It would be non-
corrosive, could be made very light
in weight, and is the material rec-
ommended for all metal couplings

8

on nonmetallic pipe. Methods of
manufacture developed during this
war have greatly reduced the cost
of stainless steel. Its expense would
be divided over the whole pipe line
assembly and would therefore be
reasonable as it would occupy only
one-thirtieth of the length of the
line.

Joint No. 6 was the first trial of a
full asbestos-cement joint. A cou-
pling of 6-in.-i.d. 200-lb. pipe was
threaded, one thread to the inch, and
connected to two sections of 5-in.-i.d.
200-lb. pipe similarly threaded. The
thread on the pipe was tapered.

Joint No. 7 was of the same size
as joint No. 6. The taper was such
that the cross-section of the pipe
and of the center of the coupling
were equal. The asbestos-cement
couplings for joint Nos. 6 and 7
lacked the elastic gripping power
which is present in steel and plas-
tic couplings.

Tests on Asbestos-Cement Pipe

Compression. — A section of 3-in.-
i.d. flue pipe was destroyed by com-
pression in the apparatus shown in
Fig. 5 at the Talbot laboratory, Uni-
versity of Illinois, under the direc-
tion of Professors Frank Richart and
V. P. Jensen. It failed at 14,000 lb.
It was not destroyed in tension but
it was evident that it would give a
poor account of itself. The material
is low grade.

Bursting. — A section of 5-in.-i.d.
200-lb. pipe shown in Fig. 2 (top)
was tested at the factory to 800 psi.
without failure. The ultimate
strength is 1,100 psi.

Collapse. — The section of pipe
shown in Fig. 2 (bottom) was sub-
jected to 2,000 psi. compression with-
out failure at the Bradford Supply
Shop at Robinson, 111. The section
shown in Fig. 2 (top) was tested to
1,750 psi. without failure. This speci-
men consisted of two sections of 4%-
in.-i.d. 200-lb. asbestos-cement pipe
connected by a pitch fiber coupling.
The pipe was prepared by machin-
ing the ends of the pipe, placing
a rubber gasket at each end, and
fitting them with metal caps con-
nected through the pipe with a rod
which was tightened with nuts on
each end of the rod where it ex-
tended through the cap.

The pipe to be tested was placed
inside a 7-ft. joint of extra heavy
10-in. casing ending in couplings
into which were screwed swedged
nipples, one of which was connected
to the hydraulic pump and the other
to an outlet valve. Air was released
at a valve on the top side of the
casing.

Valves on the pump would not
hold beyond the 2,000 and 1,750-lb.
pressures. When removed from the
casing the asbestos-cement pipe was
undamaged.

These tests prove that the pipe is

Fig. 8 — A 2-in. plastic coupling connected to pipe ready lor a tsnsile tsst and the same
coup/ing alter testing to destruction. The threads did not strip. The coupling parted
through the last thread at the center. Reinforcement would give increased fensiJe strength

COILED WIRE REINFORCEMENT FOR FIBRE PIPE

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METHOD OF ROTATING PIPE TO FORM CEMENT INTERLINING

METHOD OF MAKING REINFORCED CEMENT-LINED FIBRE PIPE

Fig. 9 — Illustration of method of lining fiber conduit with cement. Cement lining
increases power to resist collapse and metal reinforcement prevents bursting

competent to withstand ordinary
salt-water-disposal loads.

Tests for Tensile Strength

Tests for tensile strength were
made on the apparatus shown in
Fig. 5, at Talbot laboratory, under
the direction of Professors Richart
and Jensen. They were made pri-
marily to investigate the possibility
of using the pipe for cemented-in
casing for salt-water-disposal wells.

Joint No. 3 (see Figs. 2 and 3)
failed in the thinnest part of the
pipe next to the type-metal mechan-
ical bond at 4,600 lb. The material
was low-grade flue pipe and the
result is not comparable with the
other results described.

Joint No. 4 (see Figs. 2 and 3)
failed in the thread at the outer
edge of the coupling at 20,200 lb.

Joint No. 5 (shown on Figs. 1 and
5) went to 12,700 lb., at which point
the plug in the end of the pipe
pulled out and the test had to be
stopped. On a later test, after the
plug had been reset, the thread on

the transite pipe stripped at 22,000
lb. This was an important finding
as it proved that shallow threads
cut on asbestos-cement pipe had
great strength.

Joint No. 6 (Figs. 2 and 3) with-
stood a pull of 28,700 lb., at which
point the pipe pulled apart at the
point where the pins holding the
rod weakened the pipe.

Joint No. 7 (Fig. 1 only) failed in
the last thread at center of the cou-
pling at 29,200 lb.

Joints No. 1 and 2 were not tested
for tensile strength.

These tests show that tensile
strength is sufficient for loads usual
in salt-water disposal through sur-
face lines and for cemented-in cas-
ing for shallow wells.

Tests for Tightness of the Joints
Against Leakage

All the joints from No. 3 to No. 7
inclusive, were tested for leakage
with a setup as shown in Fig. 6.
Three pressures were used: (1) water

10

Fig. JO — A metal
coupling the project-
ing thread o/ which
has a thin sec/ion.
and asbestos ce-
nt e n t pipe the
thread c/ which
has a thick section.
This is an attempt
to proportion the
cross-section o/ each
materia] to its rela-
tive strength to re-
sist stripping

at city pressure of 55 psi.; (2) water
at pump pressure of 100 psi.; and
(3) air at 200 psi. Rubber gaskets
were used in most cases but gaskets
made of fabric and graphite were
equally effective. All the joints were
leakproof at the pressures applied,
but when used as casing higher
pressures will be encountered.

Glascrete

In an effort to find a material
which would have the corrosion-re-
sistant qualities of cement pipe and
not require the use of asbestos, a
scarce material, experiments were
tried with cement reinforced with
glass fiber. The pipe could not with-
stand shock although it proved to be
a fairly satisfactory material to with-
stand slowly applied loads. Fig. 7
shows the press and dies with which
the pipe was made and the rein-
forced pipe in the hydraulic testing
machine. Glass fibers are pictured
between the press and the dies. The
same apparatus was used in making
and testing plastic couplings.

Results from tests show too much
variety to lead to dependable con-
clusions, but even if the results un-
der slowly applied loads could be
duplicated in manufacture, the ma-
terial would be too brittle for oil-
field usage.

Asbestos-Cement Pipe With Metal
Couplings

Asbestos-cement pipe is practical
for oil-field surface lines to conduct
salt water, and when cemented in it
is competent as casing for salt-water-
disposal wells of moderate depth.
Greater depths may be cased if the
casing is floated into a hole full of

fluid. The strength of threaded metal
couplings on threaded asbestos-ce-
ment pipe has been demonstrated
in the test of the 5-in. asbestos-
cement pipe coupled with a 6-in.
steel coupling. Stainless steel com-
bined with asbestos-cement pipe
provides a corrosion-proof casing
and pipe line.

Plastic Couplings

Fig. 8 shows a 2-in. plastic cou-
pling set up for a test to destruction
by tension and the coupling after
destruction. This was pulled apart
in the Talbot laboratory at 2,890 lb.
The area of plastic is 3.4 in., so that
the strength is 825 psi. A plastic cou-
pling to connect two joints of %-in.
by 6-in. asbestos cement pipe would
have to be 1.1 in. thick to make the
plastic coupling and asbestos-ce
ment pipe of equal strength. Since
this is rather thick, its cross-section
may be reduced by reinforcement.
Reinforcing plastics with glass fiber
is very successful, and metal rein-
forcement has given promising re-
sults (see Fig. 12). By either rein-
forcing means, the cross-section of
the plastic coupling may be greatly
reduced at no expense of strength.
The use of plastics instead of cement
for protection behind metal or for
strength behind nonmetallic casing
for wells presents interesting possi-
bilities.

Conclusions

Perfecting of corrosion-proof pipe
lines and cemented-in casing has a
postwar as well as a wartime use.
The investigations outlined in this
article are a start in this direction.
They demonstrate that asbestos-

1 1

Fig. J J— (Right) Up-
per figure: High-
speed grinding
equipment mounted
on ordinary lathe,
used /or grinding
exterior and interior
threads on asbestos
cement or plastic
pipe and couplings.
Lower figure: De-
rice for sharpening
abrasive wheel

Fig. 12— (Left) Short
section of plas-
tic pipe, reinforced
with parallel metal
rods contacting spi-
r a 1 reinforcement.
The pipe has been
ground down to ex-
pose reinforcement
which normally
would be entirely
covered by plastic

12

cement pipe may be successfully
threaded by grinding and joined by
stainless steel or plastic threaded
couplings to form a line sufficiently
strong to provide practical pressure
surface lead lines and may be ce-
» f* mented in as casing in wells of con-
t siderable depth for oil-field salt-
, water disposal. Strings of corrosion-
proof pipe to take smaller loads for
the same purposes may be made of
threaded fiber pipe united with
plastic couplings, and reinforced ce-
ment-lined fiber pipe may be used
for intermediate pressures and
depths. Plastic couplings may be re-
inforced with glass fiber or metal
and used to join either asbestos-
cement or fiber pipe.

Acknowledgments

The writer wishes to thank the follow-
ing for help on this problem: B. G. Le-
Mieux of Fibre Conduit Co., of New York
City; Frederick Heath, Jr., of Owens-Corn-
ing Glass Corp., Toledo, Ohio; T. N.
Thomason, of Corning Glass Works, Corn-
ing, N. Y.; Wirt Franklin, formerly of
PAW, Chicago; W. C. Hale of South Ches-
ter Tube Co., South Chester, Pa.; Halli-
burton Oil Well Cementing Co., Duncan,
Okla.; L. P. Lessard and E. W. Rembert,
of Johns-Manville Co., New York; Robert
G. Melton, of the research department of
Keasbey & Matteson, Ambler, Pa.; Carl
Lowrence, of Bradford Supply Co., Rob-
inson, 111.; R. R. Bradshaw, of Dow Chem-
ical Co., Midland, Mich.; F. E. Richart,
and F. P. Jensen, of the Talbot laboratory,
University of Illinois; A. H. Bell, A. W.
Gotstein, and Robert Urash of Illinois
State Geological Survey.